Determinimg Minimum for Model Distance Legibility of Guide Signs Based On Volume of Information

With the increasing population and with the increasing demand for transport, State Highway Network developed, and traffic equipment for increase their safety in more feel. One of the most important equipment that related to road safety is guide signs. So For this purpose, the guide signs must have the best performance. Therefore , To assess legibility of guide signs, in this study , after designed two series of Guide Signs ; that the first series and a second series consists of 21 signs and 28 signs were ; By using software DMDX , with regard to conditions , Perception-Reaction Time (PRT) of Reading Signs Registered by users and saved in the system . Finally, with regard to restrictions on the viewing angle and the factors affecting it, the final model is the minimum distance legibility of guide signs is based on the volume of information presented.